Li Bei-Bei, Qin Jian-Ping, Qi Li-Rong, Yang Tao, Qu Song, Shi Ai-Jun, Huang Yu-Hu
College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China.
National Engineering Research Center of Urban Environmental Pollution Control, Beijing Municipal Research Institute of Environmental Protection, Beijing 100037, China.
Huan Jing Ke Xue. 2018 Mar 8;39(3):1031-1039. doi: 10.13227/j.hjkx.201708109.
This study characterized the wind erosion dust emissions from topsoil of urban roadside-tree pool. The study area is the Xicheng District of Beijing and uses GIS to obtain the spatial distribution of various road mileages. A full bore investigation method was carried out to survey tree pool in the Zhanlanlu Subdistrict to obtain the activity level of tree pool in the Xicheng district. The portable in situ wind erosion laboratory (PI-SWERL) was used to determine the emission factors of PM from the wind erosion dust from tree pool and to estimate the PM emission inventory of tree pool in the Xicheng District in 2016. The results showed that:①The annual emission factors per unit area of PM from tree pool of freeways' frontage roads, major roads, minor roads, and alleys are 47.9, 7.9, 14.9, and 29.9 g·(m·a), respectively. The reduction rate of PM emission factors from tree pool by precipitation was about 30.3% in 2016. ②The annual emission factors per unit mileage of PM from the tree pool of freeways' frontage roads, major roads, minor roads, branch roads, and alleys are 2.57, 2.33, 4.04, 7.31, and 5.44 kg·(km·a), respectively, and the factors for branch roads are 1.3, 1.8, 2.8, and 3.1 times as much as those for alleys, minor roads, freeways' frontage roads, and major roads, respectively. Taking the emission factor for minor roads as an example, the winter emission factor is 1.3, 7.3, and 8.7 times greater than that in the spring, summer, and autumn, respectively. ③PM emissions from the tree pool in the Xicheng District of Beijing are 1.60 t·a, and the uncertainty range of the emission inventory is -143%~184%. The emissions in winter are 0.68 t·a, which are 1.1, 1.42, and 5.1 times greater than that in the spring, summer, and fall, respectively. The emission values for freeways' frontage roads, major roads, minor roads, collectors, and alleys account for 5.6%, 8.7%, 23.2%, 4.1%, and 58.4% of the total emissions, respectively. It is recommended that the urban roadside-tree pool be covered to reduce wind erosion dust emissions with materials that do not affect the growth of trees as soon as possible.
本研究对城市路边树池表土的风蚀扬尘排放特征进行了表征。研究区域为北京西城区，利用地理信息系统（GIS）获取各道路里程的空间分布。采用全口径调查方法对展览路街道的树池进行调查，以获取西城区树池的活动水平。使用便携式原位风蚀实验室（PI-SWERL）测定树池风蚀扬尘中颗粒物（PM）的排放因子，并估算2016年西城区树池的PM排放清单。结果表明：①高速公路临街道路、主干道、次干道和小巷树池PM单位面积年排放因子分别为47.9、7.9、14.9和29.9 g·(m·a)。2016年降水对树池PM排放因子的削减率约为30.3%。②高速公路临街道路、主干道、次干道、支路和小巷树池PM单位里程年排放因子分别为2.57、2.33、4.04、7.31和5.44 kg·(km·a)，支路的排放因子分别是小巷、次干道、高速公路临街道路和主干道的1.3、1.8、2.8和3.1倍。以次干道排放因子为例，冬季排放因子分别是春季、夏季和秋季的1.3、7.3和8.7倍。③北京西城区树池的PM排放量为1.60 t·a，排放清单的不确定性范围为-143%~184%。冬季排放量为0.68 t·a，分别是春季、夏季和秋季的1.1、1.42和5.1倍。高速公路临街道路、主干道、次干道、支路和小巷的排放值分别占总排放量的5.6%、8.7%、23.2%、4.1%和58.4%。建议尽快用不影响树木生长的材料覆盖城市路边树池，以减少风蚀扬尘排放。
